Big Dog K9 shuts down and horn sounds after 10 min of running

Energy One

2007EZ

Member
I am new to Big Dog motorcycles and recently bought a 2007 Big Dog K9. As I write this thread I can hear many of you saying "Not another electrical thread". I have searched throughout the forum, online, the manual, and spent a month of on and off troubleshooting without solving the problem. The issue, my bike will shut off after about 15min of idling, or shortly after I start riding down the road. The horn will turn on, and stay on, along with the flashers until its turned off. I have to turn it on and off a few times before the bike can be restarted. Below is what I have tested/replaced so far:

Battery--New, 12.8v and passes load test. All battery connections tight and crimped correctly.
Stator--Produces correct voltage with increasing RPM's. The Ohm measurement is .3 but after 1-2 seconds will drop to .2. Could this error be low resistance indicating the stator needs to be replaced??
Voltage Regulator--Tested Bad. I thought that this was the primary issue. Replaced with new Compu-fire VR and the problem is still present.
Handle Bar controls--I have taken both off and cleaned the connections and applied dielectric grease.
Wire Harness--I have inspected the wires under the gas tank, under the bike, turn signals, headlight, and found no damaged or loose connections. New dielectric grease on all connections.
EHC--Run light on after run button pressed. Horn light will be lit after bike shuts off and horn sounds. No other lights are lit. I have removed the connections, inspected, and reapplied dielectric grease.
Circuit Breaker--New part. No change in voltage across the pins and continuity is present.
Ignition Module--Red light lit. When running, yellow and blue light work correctly.
Ignition switch--wiggled key when the bike is running and didn't cause an issue.

The only other potential problem would be the pulse count on the speedometer or voltage drop measured when starting the bike. I have removed, inspected, and cleaned the speedometer connections, finding no issues. However, when starting, the pulse count is 49438. The manual states it should be 49440. Any issue there? When starting the bike, the voltage would drop to 9v if the starter was pressed more than twice, but would immediately return to 12.8v and start with no issues. Besides sending the EHC out for testing, is there something I should test, or could be missing?

Thanks in advance for any help provided!
 

Sven

Well-Known Member
The issue, my bike will shut off after about 15min of idling, or shortly after I start riding down the road.
My engine warms up, 15 minutes in the bike stalls. Heat into the cam or crank sensor within 15min and the bike shuts off. I have to immediately crank the bike to see if I have spark? Why? The sensor is hot and fails. Sensor cools it refires.

The horn will turn on, and stay on, along with the flashers until its turned off. I have to turn it on and off a few times before the bike can be restarted.
1. I have to cycle the key to turn the noise and light show off? Or I have to turn the key on and off so spark reappears?
2. I have the bike off the side of the road. I cycle the key a few times and it fires back up. Yes or no? Why? Because this says it's not the crank or cam sensor heating up if you toggle the key fob and it lights back up again within minutes.
3. I have this constant 15 minutes of running and then cuts out. Yes or no?
4. I let the bike idle for 15 minutes and not move it to cool it off. So the heat off this air cooled engine begins to boil the fuel in the fuel line I have a hard time starting it. Why are we sitting with an air cooled engine for so long? Is this every time is the routine?
5. I seem to find that if I use the turn signals is when it occurs. How close are we messing with the winker switch if the horn button is on the same switch as the winkers? See how it's shorting out the winks and horn, or is this a verbal check engine light, where the shop manual mentions all the winks and horn hits mean something to look for?
6. I have winks coming on as if triggered or short to ground? So if I remove the winker/horn switch connector out of the loop, I have less wire shorting to ground, the bike no longer stalls with connector removed... yeah, a long shot.

Recap:
I'm with new spark plug in pocket. I stall, I install the new plug, short it to the head and look for spark. This is my cam or crank sensor losing spark when heated, returns when cooled... key fob noted.
I'm assuming this info about sitting for 15 mins with no air running past the engine, the gas begins to run air bubbles up the jets, not solid fuel about to be bubbled or atomized farther up the jet tube.
I'm stumped with the key cycling as in this move refires the bike. This then says no boil, no sensor, no blown fuses but points to the black box as in RAM wipe and the bike fires.
 

2007EZ

Member
I am not sure that I understand your response. I have checked the crankcase position sensor by using a heat gun to bring the crankcase sensor up to operating temperature before starting. This did not effect the operation of the bike and it still stalled after about 10-15 minutes of idling. Also, while the bike was running, I tapped on the sensor and this did not effect the idle or make the bike RPM fluctuate.
 

Little-Boo

Well-Known Member
Troop Supporter
I am not sure that I understand your response. I have checked the crankcase position sensor by using a heat gun to bring the crankcase sensor up to operating temperature before starting. This did not effect the operation of the bike and it still stalled after about 10-15 minutes of idling. Also, while the bike was running, I tapped on the sensor and this did not effect the idle or make the bike RPM fluctuate.

Nobody ever does :oldlaugh: :oldlaugh:, don't feel like the Lone Ranger. Looks like you have done just about all that I would do. However, my experience with the horn going off and staying on mean that the horn relay took a shit and is probably working intermittent. Replace it and see If that takes care of the horn issue.

Carlos
 

Sven

Well-Known Member
I am not sure that I understand your response.
I am trying to understand why someone would let an air cooled engine sit for literally 15min and do what with it? I'm not going to run down the street with an extension cord coiled up and I'm reaching over at the crank sensor as I ride down the road with a hair blower. We understand we are looking for 6 simple variables and we have yet to clear the first 3?

Fuel = I sit for 15 minutes is the info brought in. It sure is running and not about to cause heat to cook the parts or does it? I now ride down the road and more heat comes off the bike, boils the carb or injector tubes, who the fuck knows? We understand 15 fucking minutes?

Spark = I shut the fuck down. Hurry! Do I have spark when I am stopped? Hurry, stand up, pull my plug out of my trouser pocket, hurry! Pull the plug wire, install the plug, ground the fucker... Do we have SPARK?

Compression = The fucker runs. Forget this one totally!

We have now passed our 3amigos as you do not understand this.
We now find out if WATTheFucks works?

Trigger = I fucking reset and start. Get it?
Threshold = I'm fucking waiting for the bike to reset because it fucking starts.
Discharge = I finally discharged and started again. I am not shorted out are the parts.

How the fuck am I doing now?
Now, can you figure out how I have 15 minutes to play wit chew fucking with the bike? Is it fuel or is it the box? Is it the sensor or is it a simple short you go bouncing as you ride and it pinches something out? No. It comes back on line, right? Comes back on line means it fires back up, yes? No fuses blown, right? No short you'd think.

Fuel or spark? Who is missing I pull up my trousers and look like fucking quick!
 

Sven

Well-Known Member
However, my experience ... the horn relay took a shit
Carlos
I think I also covered to loophole the connector not being connected so the horn was out of the loop. Would it trigger the relay on its own? Is the relay anywhere near the kill or inline with ignition, etc.? Would this TTD the box and the relay stays open (+), kills spark, relay is turned off by the key, starts again when the relay cools?

Relay goes into plug-3 and up to a 'switch module' then to plug-2. But at plug-3 is the relay wire #3 and the 'ignition module' is wire #5. Both use the same plug, both enter whatever the switch mod is? Pull the relay connector off. Take it for a ride.
 

FrankBDPS

Well-Known Member
If you are letting the bike sit and idle with no cooling for 15 minutes you are soon to have lots more serious issues. The bike will not charge at an idle. You are killing the battery and like Sven says you are over heating everything including some very expensive ignition parts.

What brand name battery are you running. Most problems like this go right back to a bad battery.

Good luck.
 

2007EZ

Member
In troubleshooting the bike I have only let it sit idle for 15 minutes about 2-3 times. If the bike doesn't shut off in the first few minutes I will take it out for a ride around the block, but every time I take out for a ride it will shut off and the horn and flashers will turn on. My battery is a Super Start Extreme AGM ETX20L with 310CCA @ 17.5Ah. I have looked into Deka and Duracell and they both have the exact same ratings.

Fuel and spark--To eliminate these as an issue, I drained the gas tank, when it was off to inspect the wires, cleaned the petcock valve and replaced the fuel, and added stabilizer. Spark--This has never been an issue. The bike will always start and run good with exception to a few back fires after revving the bike.

The hand controls do not cause the bike to shut down and they all work correctly.
 

2007EZ

Member
My engine warms up, 15 minutes in the bike stalls. Heat into the cam or crank sensor within 15min and the bike shuts off. I have to immediately crank the bike to see if I have spark? Why? The sensor is hot and fails. Sensor cools it refires.


1. I have to cycle the key to turn the noise and light show off? Or I have to turn the key on and off so spark reappears?
2. I have the bike off the side of the road. I cycle the key a few times and it fires back up. Yes or no? Why? Because this says it's not the crank or cam sensor heating up if you toggle the key fob and it lights back up again within minutes.
3. I have this constant 15 minutes of running and then cuts out. Yes or no?
4. I let the bike idle for 15 minutes and not move it to cool it off. So the heat off this air cooled engine begins to boil the fuel in the fuel line I have a hard time starting it. Why are we sitting with an air cooled engine for so long? Is this every time is the routine?
5. I seem to find that if I use the turn signals is when it occurs. How close are we messing with the winker switch if the horn button is on the same switch as the winkers? See how it's shorting out the winks and horn, or is this a verbal check engine light, where the shop manual mentions all the winks and horn hits mean something to look for?
6. I have winks coming on as if triggered or short to ground? So if I remove the winker/horn switch connector out of the loop, I have less wire shorting to ground, the bike no longer stalls with connector removed... yeah, a long shot.

Recap:
I'm with new spark plug in pocket. I stall, I install the new plug, short it to the head and look for spark. This is my cam or crank sensor losing spark when heated, returns when cooled... key fob noted.
I'm assuming this info about sitting for 15 mins with no air running past the engine, the gas begins to run air bubbles up the jets, not solid fuel about to be bubbled or atomized farther up the jet tube.
I'm stumped with the key cycling as in this move refires the bike. This then says no boil, no sensor, no blown fuses but points to the black box as in RAM wipe and the bike fires.
I am trying to understand why someone would let an air cooled engine sit for literally 15min and do what with it? I'm not going to run down the street with an extension cord coiled up and I'm reaching over at the crank sensor as I ride down the road with a hair blower. We understand we are looking for 6 simple variables and we have yet to clear the first 3?

Fuel = I sit for 15 minutes is the info brought in. It sure is running and not about to cause heat to cook the parts or does it? I now ride down the road and more heat comes off the bike, boils the carb or injector tubes, who the fuck knows? We understand 15 fucking minutes?

Spark = I shut the fuck down. Hurry! Do I have spark when I am stopped? Hurry, stand up, pull my plug out of my trouser pocket, hurry! Pull the plug wire, install the plug, ground the fucker... Do we have SPARK?

Compression = The fucker runs. Forget this one totally!

We have now passed our 3amigos as you do not understand this.
We now find out if WATTheFucks works?

Trigger = I fucking reset and start. Get it?
Threshold = I'm fucking waiting for the bike to reset because it fucking starts.
Discharge = I finally discharged and started again. I am not shorted out are the parts.

How the fuck am I doing now?
Now, can you figure out how I have 15 minutes to play wit chew fucking with the bike? Is it fuel or is it the box? Is it the sensor or is it a simple short you go bouncing as you ride and it pinches something out? No. It comes back on line, right? Comes back on line means it fires back up, yes? No fuses blown, right? No short you'd think.

Fuel or spark? Who is missing I pull up my trousers and look like fucking quick!

Read this response last night after a few drinks. Reread this morning and now I understand. When the bike shuts down I have to cycle the key a few times to get the horn to turn off and clear all the lights on the EHC. The hand controls do not effect the bike indicating a short or grounded wire.
 

Sven

Well-Known Member
When the bike shuts down I have to cycle the key a few times to get the horn to turn off and clear all the lights on the EHC.
I look at the 2007 BD wire diagram I see the relay is more like tied to the battery posts. So the other wires are tied into the black box. This means it is inside the wire plus black box. There is a black rectangle line that surrounds the switch module and the LED lights. I assume this is the wire plus black box. So internally it looks like the wires from the relay and ignition module enter into the switch module.

Might the gray wire disconnected at the relay stop the horn, but see if the lights still come on? This way one of two things will happen.

1. The gray wire completes a loop with the ignition module and will not start the bike.
2. The gray wire is no longer hooked up to the relay [if faulty], bike starts and does not need to complete a circuit to make the coil spark.
3. Conclusion: Once the relay kicks in the lights, does not or cannot be triggered internally, because the relay is out of the loop with the one [gray] wire disconnected and won't work anyway, the bike continues to run. Do we point at the relay? Do we point at the black box? Bike stopped without the relay in play.


If the key has to cycle and bike to start it again, sure sounds like the inputs [jobbers] work. The output fails and that points to the black box if the receiving jobber works.

So, jobber in is the crank sensor. Jobber out is the coil.
So, key fob my black box is the middleman being the problem; the crank sensor keeps sending in a good signal each time; the coil continues to fire, the key switch keeps connecting the dots so it starts.
So, process of elimination, you covered all the bases, keep disconnecting non essentials like the relay, winker switches, any switch off the black box that does not shut the bike down.
So, all connectors are off and it comes down to the black box taking a shit, no ping to short it to ground from the input sides.
So, ignition module keeps firing. Coil keeps firing. Crank keeps square waving. Relay comes into play is one more variable. Make sense?
 

Sven

Well-Known Member
I would assume so. I'm also going to assume the trigger to the relay will still stall the bike>> even if the relay was disabled. I'm sure you covered a lot of track. I'm going to assume the bike never stalled for those 15 minute tests, right? I'm going to assume the neck was not moving as if you were steering it, right?

But if you ran it for 15 minutes or less, she stalls on the side of the road, yes? So now I want to let the bike idle, grab the wire harness at the steering neck and push, tug, rub the harness on the frame as if steering the bike a lot... the question is, will it stall with a loose, broken, frayed wire at the neck area... unless you tried this with the bike idling for that long, yes?
 

2007EZ

Member
I would assume so. I'm also going to assume the trigger to the relay will still stall the bike>> even if the relay was disabled. I'm sure you covered a lot of track. I'm going to assume the bike never stalled for those 15 minute tests, right? I'm going to assume the neck was not moving as if you were steering it, right?

But if you ran it for 15 minutes or less, she stalls on the side of the road, yes? So now I want to let the bike idle, grab the wire harness at the steering neck and push, tug, rub the harness on the frame as if steering the bike a lot... the question is, will it stall with a loose, broken, frayed wire at the neck area... unless you tried this with the bike idling for that long, yes?
This morning I took the bike out. I let it warm up for about 2 mins then set out around the block. Within two blocks from my house the bike shut off again (this is the usual spot where the bike will shut off and turn on the horn/flashers). I turned the bike on and off a few times to clear the flashers/horn. This time I noticed something new after the faults were cleared. I turned the ignition on, (while talking to a neighbor who came out to help) and I noticed that the speedometer did a second sweep of the MPH gauge after about 2 minutes of the key being in the on position, then the hazard lights started flashing. After about 20 times of cycling the key, the hazard lights and horn cleared and I was able to start the bike to drive home. Got home and turned the bike off and went to get some tools/DMM. When I got back I turned the ignition on and the hazards/horn were on again. I cycled the ignition to clear the fault then started the bike then started to move the wires coming from the steering neck, no change to the bike.

To eliminate the speedometer, tach ring, and horn, I disconnected them and turned the ignition to the on position, no starting. After about two minutes the flasher lights came on along with the horn. It is now harder to clear the faults even with the bike being cooled down. Any thoughts?
 

Sven

Well-Known Member
It is now harder to clear the faults even with the bike being cooled down. Any thoughts?
That's for the EE's around here. Every time I try to guess I throw another variable at it and it blows that theory. For example, who saves the value... a capacitor. But each time you ground the unit, the cap clears for the next value saved in volatile (RAM). So how could it be harder to clear if... ????

I think this should be in my mental toolbox... is to let the bike sit with key on, no start... wait for the "ping." Sounds like?... sounds like a direct short. Look at how the unit keeps the DTT going... more on the blink. So the next thought is to narrow it down.

I'd yank the wire plus off of the bike. I already wrote down my DMM prongs values off the horn and light; before the bike set the "Phantom-DTT" in motion. The bench test is with the battery alone, wait for the DTT to trigger.

There has to be one of two things occurring. Either it triggers on it's own in the remote, or there is a ground, as in a single strand is touching, it's just enough to trigger the unit when installed on the bike.
 

Sven

Well-Known Member
12v goes into the ecu so find A3 or a red wire going into the WP374. Use any black wire (mark before removing) out of the WP for ground. Use a [low amp] fuse holder inline when installing the (+) onto the battery. Use any black wire for ground, or its prong, etc.
 

TapioK

Well-Known Member
Blinkers and horn are low voltage warning.
You mentioned your VR was bad, did it by any change charge way too high voltage? If it did, EHC may be going... Send it to Curtis to check...
Or there is a shortage somewhere.
Or Alien activity in your neighborhood.


Sent from my iPhone using Tapatalk
 

2007EZ

Member
Blinkers and horn are low voltage warning.
You mentioned your VR was bad, did it by any change charge way too high voltage? If it did, EHC may be going... Send it to Curtis to check...
Or there is a shortage somewhere.
Or Alien activity in your neighborhood.


Sent from my iPhone using Tapatalk
I am going with alien activity! When I got the bike, I knew there was a potential electrical issue. The previous owner put in a new battery, and by his account that is when the electrical issues started. Since the bike sat for a few months, I went through changed the fluids and cleaned the gas tank/carb. I thought the "electrical" issue was related to the idle which would cause the bike to shut off after signaling low oil pressure. Quickly fixed that problem by adjusting the idle screw bringing the RPM's up. It worked, that is when I ran into the current problem. I am not sure if the previous owner had an issue with the VR, or an over voltage to the EHC, but it was not correctly charing the bike, and the ohm measurement proved bad, that is why I replaced the VR.
 
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